Immunonutrition

The potential to modulate the activity of the immune system by interventions with specific nutrients is termed immunonutrition. This concept may be applied to any situation in which an altered supply of nutrients is used to modify inflammatory or immune responses. However, immunonutrition has become associated most closely with attempts to improve the clinical course of critically ill and surgical patients, who will often require an exogenous supply of nutrients through the parenteral or enteral routes. Major surgery is followed by a period of immunosuppression that increases the risk of morbidity and mortality due to infection. Improving immune function during this period may reduce complications due to infection. Critically ill patients are at greater risk of adverse outcomes than surgical patients. In these patients complex variable immune and inflammatory changes occur that are only now being well defined. A biphasic response with an early hyperinflammatory response followed by an excessive compensatory response associated with immunosuppression is seen in many such patients. Here, early treatment is aimed at decreasing the inflammatory response rather than enhancing it, to abrogate the hyperinflammation and prevent the compensatory immunosuppression.